mp Co uta & tio d n e a li Ramanakumar, J Appl Computat Math 2018, 7:3 l p M p a Journal of A t h DOI: 10.4172/2168-9679.1000414 f e o m l a a n t r ISSN: 2168-9679i c u s o J Applied & Computational Mathematics Review Article Open Access Mathematically Describing Planetary Orbits in Two Dimensions Ramanakumar V* Chinmaya International Residential School, Nallur Vayal Post, Siruvani Road, Coimbatore, Tamil Nadu, India Abstract This article describes use of Mathcad mathematical package to solve problem of the motion of two, three and four material points under the influence of gravitational forces on the planar motion and in three-dimensional space. The limits of accuracy of numerical methods for solving ordinary differential equations are discussed. Usual concept of Kepler hours with uneven movement arrows in planet. Projectile motion may be thought of as an example of motion in space-that is to say, of three-dimensional motion rather than motion along a line, or one-dimensional motion. In a suitably defined system of Cartesian coordinates, the position of the projectile at any instant may be specified by giving the values of its three coordinates, x(t), y(t), and z(t). Keywords: Natural satellites; Projectile; Motion; Planetary e: Although not included in the diagram, this quantity is known as eccentricity, which is the measure of the deviation of the shape of an Introduction orbit from that of a perfect circle (a measure of how elliptical an orbit is). The higher the eccentricity of an orbit, the more elliptical it is. It One of the biggest applications of mathematics is in the field of c can be calculated using the simple formula: e = (for an orbit into astrophysics, which is the study of the mechanical motion and behavior a of celestial bodies [1]. Using math, we can describe any celestial parametric 1). phenomena using numerical quantities which represent certain After some research from wolframalpha.com and physical characteristics [2-5]. windows2universe.org, Tabulated these values for each planet. All In this theoretical paper, mathematically describe the orbits values are given in astronomical units. of natural satellites and planets, and use this to calculate certain characteristics of the orbits of the planets within our solar system [6- Cartesian Form of an Orbit 9]. Once done this using mathematical method, calculated values to Given the fact that any planetary orbit is an ellipse, the Cartesian literature values already determined. The properties of a planetary orbit form will follow the basic form of an elliptical curve: plan on investigating are: 22 ( xh−−) ( yk) 1. The Cartesian form of an elliptical orbit 1 = + ab22 2. The Parametric form of an elliptical orbit Where h is the horizontal displacement of the curve, k is the vertical 3. The Polar form of an elliptical orbit displacement of the curve a is the radius of the curve in the x direction, and b is the radius of the curve in the y direction. 4. The length of the orbit using various forms Generally, in a planet’s orbital curve, there is no displacement in the 5. The area covered by the ellipse of the planetary orbit y direction; the focus only shifts away from the origin in the x direction. 6. The volume carved out by a planet as it makes one full revolution Therefore, the value of k in the above equation for a planetary orbit around the sun. becomes 0. At first glance, the motion of planetary bodies may seem complex Now, we need to plug in the variables introduced in the previous and hard to understand [10]. However, believe Math is a black and white section. Since c is the distance between the focus, which represents subject that simplifies certain situations to numbers and equations. the origin O, and the center of the curve, this can be denoted as the In this report, it attempt to simplify planetary revolutions through horizontal displacement of the curve, so we can replace h with c. mathematical concepts. The variable a represents the semi-major axis, or the radius in the x direction, and will take the position of the variable a in the general Before proceeding with this investigation, it is important to form. The variable b represents the semi-minor axis, or the radius in the introduce and layout the basic variables and quantities that will be used y direction, and will replace the variable b in the general form equation. in this exploration [6]. These quantities are included in the diagram below: • a: This represents the semi-major axis, which is the largest *Corresponding author: Ramanakumar V, Student, Chinmaya International Residential School, Nallur Vayal Post, Siruvani Road, Coimbatore, Tamil Nadu, distance between the center of the ellipse and the curve of the India, Tel: +91 9962258783; E-mail: [email protected] orbit. Received July 08, 2017; Accepted August 20, 2018; Published August 21, 2018 • b: This represents the semi-minor axis, which is the shortest Citation: Ramanakumar V (2018) Mathematically Describing Planetary Orbits in distance between the center of the ellipse and the curve of the orbit. Two Dimensions. J Appl Computat Math 7: 414. doi: 10.4172/2168-9679.1000414 • c: This is the distance between the center of the orbit and Copyright: © 2018 Ramanakumar V. This is an open-access article distributed the focus of the orbit, which is where the Sun would be in a under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the planetary orbit. original author and source are credited. J Appl Computat Math, an open access journal Volume 7 • Issue 3 • 1000414 ISSN: 2168-9679 Citation: Ramanakumar V (2018) Mathematically Describing Planetary Orbits in Two Dimensions. J Appl Computat Math 7: 414. doi: 10.4172/2168- 9679.1000414 Page 2 of 7 With the given replacements and adjustments, we get the general Cartesian form for the elliptical orbit of a planetary body: 22 ( xc− ) ( y) 1 = + ab22 Parametric Form of an Orbit The parametric form of an equation expresses both variables in a function, x and y, in terms of another distinct variable. In this paper, we will refer to this variable as t (not to be confused with the variable for time). We can convert our Cartesian equation for an orbit into parametric form in a few simple steps: 22 22 ( xc− ) ( y) xc− y Figure 2: The sum of the lines F P and F P is equal to equal to 2a. 1 = += + 1 2 ab22 a b 2 (sintt )2 +=( cos) 1 xc− sint = a asin tcx+= and y cost = b bcos ty= . Polar Form Polar form equations are in terms of r, the distance from the origin, and θ, the angle between the line that connects a point on the curve and Figure 3: Point P is on the semi-minor axis, both F1P and F2P are equal to a. the origin and the positive x-axis. It attempted to directly convert the Cartesian equation to the foci and point P. Using Pythagoras theorem, we can deduce that polar equivalent, but was quite unsuccessful. It decided to manipulate b2=a2-c2 (Figure 3). some key characteristics of an ellipse to derive the polar form. The two Now, if we were to set F as the origin and let F some point on the characteristics of an ellipse to keep in mind are as follows: 1 2 positive x-axis denoted by (2c, 0), we get the in Figure 4. 1. In an ellipse, with two foci (equidistant from the center/origin), We take w to be a vector connecting O and P. The vector connecting the sum of the lines F1P and F2P are always equal to 2a, where P is any point on the ellipse (Figures 1 and 2). F2 and P is represented by w–2ci (the i is added to give direction to the magnitude 2c). The sum of the magnitude of both vectors is equal to 2a, 2. If the first diagram is altered slightly, so that point P is on the according to the first statement made above: semi-minor axis, both F1P and F2P are equal in length at a, and 2 right angle triangles are formed between the center/origin, both w+− w22 ci =a Since the magnitude of w is equal to r (recall that r is the distance between the origin and the curve), we get: ra+−w22 ci = Now we need to split the w–2ci vector into x and y components. We can denote the magnitude of the y component simply as y, but for the x component, we need to take into account 2ci, as this is in the x direction (Table 1). Therefore, the magnitude of the x component is x–2c: r+−( x22 c) i += yj a The magnitude of the second vector is nothing but the square root of the sum of the squares of the x magnitude and y magnitude: 2 ( xc−+2 ) y2 . c Remember that in polar equations, x=γ cos θ and y=γ sin θ. Figure 1: Elliptical calculated using the simple formula: e = . a Plugging these into the original equation gives: J Appl Computat Math, an open access journal Volume 7 • Issue 3 • 1000414 ISSN: 2168-9679 Citation: Ramanakumar V (2018) Mathematically Describing Planetary Orbits in Two Dimensions. J Appl Computat Math 7: 414. doi: 10.4172/2168- 9679.1000414 Page 3 of 7 Using Desmos Online Graphing Calculator, it graphed the equations for the orbits of all 8 planets to get a two dimensional aerial view of the planetary orbits.